The present invention, in general relates to an apparatus for maintaining desirable environmental conditions suitable for a terrarium, and more particularly, to an integrated environmental sustaining apparatus that can simultaneously regulate temperature levels inside and can deliver water droplets to a terrarium.
A terrarium is a man-made, enclosed habitat suitable for keeping and raising plants and animals for observation or research. Typically, the temperature and relative humidity levels inside the terrarium must be maintained within a certain predetermined range. Further, delivery of water droplets in the form of rain or mist may be required to mimic a natural environment to maintain optimum conditions for the plants and animals inside the terrarium.
Temperature control is achieved by either a global control mechanism or a local control mechanism. If a terrarium environment is kept inside a room, the entire room can be kept within a pre-determined temperature range by a conventional air conditioning system that can provide both heating and cooling. Air internal to the terrarium will generally reach thermal equilibrium with room air surrounding the terrarium with the aid of either natural convection or forced convection (i.e. a forced air circulation system inside the terrarium) between container walls and air inside the terrarium. Such a global temperature control system, when properly sized and controlled, works well. Since the global temperature control system keeps the room, in addition to the terrarium within a predetermined temperature range, operating cost is relatively high. More importantly, the existence or the wellbeing of the terrarium depends on the existence of the room air conditioning system.
Alternatively, temperature control of a terrarium can be achieved locally, independent of the room environment within which the terrarium resides.
One way to maintain the air temperature inside a terrarium above a predetermined low temperature setting in a cold weather is to apply one or more heat pads to one or more exterior walls of a terrarium. When heat pads are powered on, heat is transferred from the pads to the walls primarily through conduction, and from the heated walls to the interior air through natural or forced convection depending on whether there exists a forced air circulation system inside the terrarium. A thermostat is typically used to control power to the heat pads based on temperature measurements inside the terrarium by one or more temperature sensors.
To maintain the air temperature below a predetermined high temperature setting in warm or hot weather, cooling must be provided to the terrarium. Conventional compressor based air cooling system can be used to remove heat from inside the terrarium. Efficient delivery of cooling is typically achieved by a forced air circulation system that generally includes a fan/blower and ductwork that is thermally coupled with the cooling generating system.
For humidity control, since a terrarium is generally a significantly enclosed container, humidity can simply be maintained at a high level that is suitable for a terrarium as long as there is water in the container.
However, providing rain or mist to terrarium must be accomplished independent of temperature regulating mechanism. Typically, rain or mist is provided to a terrarium system by a water droplet delivery system driven by a water pump. Generally, the terrarium can be adapted to support an internal water reservoir that is deep enough to keep the inlet of the water pump submerged; water can be drawn from the internal reservoir to provide rain and mist. In a well-covered terrarium, there is generally very little evaporation from inside of the terrarium to the outside, and the terrarium is generally kept in an equilibrium state in terms of overall water level. As such rain or mist can be provided as frequently as needed without frequent human intervention to add water into the terrarium.
In summary, to maintain a terrarium, one will need a temperature regulating system which comprises one or more devices that can generate heating and cooling and, for a local temperature regulating system, an air circulating system to deliver heating or cooling air inside the terrarium. One will also need a rain/mist generating system. Typically, the temperature regulating system is controlled by a thermostat and the rain/mist generating system by a time control device, or a timer. As such, a typical terrarium maintenance system comprises at least two separate sub-systems that are controlled separately.
Therefore, there exists a need for an integrated environmental sustaining apparatus for terrarium systems to simplify terrarium maintenance.